WEATHER BUREAU. 183 



The library continues to make all translations from foreign lan- 

 guages required in the bureau; to supervise the small libraries main- 

 tained at about 200 stations ; and to perform the work at the central 

 office in connection with promotion examinations. All these classes 

 of work have grown steadily during the past year. 



Several station libraries have been strengthened by the addition 

 of important works in German and French, dealing with branches 

 of meteorology that are not adequately treated in English. This 

 applies especially to the literature of atmospheric electricity, atmos- 

 pheric optics, and climatography. 



In recording the growth of the hbrary it appears proper to mention 

 specifically a few of the more important meteorological works pub- 

 lished in the course of the year, copies of which have been received. 



Doubtless the greatest interest in this connection attaches to the 

 completion of J. Hann's Handbuch der Klimatologie, third edition, 

 of which the third and final volume has recently appeared. This 

 work, in its successive editions, is the only extensive treatise on the 

 climates of th'C world published during the past 20 years. 



W. Trabert's Lehrbuch der Kosmischen Physik (Leipzig, 1911) is 

 the most noteworthy recent publication belonging to the class of 

 general textbooks of meteorology. A long-awaited new edition of 

 the International Cloud Atlas has appeared. It introduces few 

 changes in the existing classification of clouds, officially adopted in 

 all countries. 



Aerology and aeronautical meteorology engage the attention of a 

 rapidly increasing number of writers. Dr. Franz Linke's Aero- 

 nautische Meteorologie, the first volume of which was recently pub- 

 lished, is the prototype of a class of books likely to become common. 

 It is a practical handbook dealing with the branches of meteorology 

 of special interest to aeronauts. A third edition of Moedebeck's 

 Taschenbuch fiir Flugtechniker und LuftschifTer is, hke the earher 

 editions, strong in the meteorological branches of the subject. Messrs. 

 A. L. Rotch and A. H. Palmer have issued a novel series of Charts 

 of the Atmosphere for Aeronauts and Aviators. The British Gov- 

 ernment has published a noteworthy Report of the Advisoiy Com-, 

 mittee for Aeronautics, 1909-1910, containing several papers by the 

 director of the meteorological office. 



The Carnegie Institution has published the first volume of a work 

 on Dynamic Meteorology and Hydrography, by Prof. V. Bjerknes and 

 others. Its object is to present the fundamental facts and principles 

 of the subject in a form suitable for treatment by the mathematical 

 physicist, in part according to methods not heretofore apphed. 



Dr. B. Walter has described an ingenious method of photographing 

 lightning flashes with two cameras, one moving and the other station- 

 ary. (Cber Doppelaufnahmen von Blitzen, Hamburg, 1910.) Dr. 

 Siiring has contributed an important treatise on meteorological pho- 

 tography to K. W. Wolf-Czapek's Angewandte Photographic in 

 Wissenschaft und Technik, vcjlume 1 (Berlin, 1911). 



Important works on the circulation of the atmosnhere included 

 The Trade Winds of the Atlantic Ocean, published by the British 

 Meteorological Office; W. J. S. Lockyer's Southern Hemisphere Sur- 

 face-air Circulation, published by the British Solar Physics Commit- 

 tee; and a fourth installment of H. H. Hildebrandsson's Quelques 



